This invention relates to archery bow sights, more specifically archery bow sights that provide for the sight, or part of the sight, to be vertically adjusted.
Archery, whether for hunting or for target shooting, requires using two hands to position a bow in such a manner as to direct the flight of an arrow towards either quarry or a target. In using a bow, an archer must realize and compensate for the rise and fall of an arrow due to trajectory and gravity. As the distances between archer and target increase, the rise and fall of the arrow has a greater importance and requires a greater initial trajectory above horizontal. As the distance becomes greater, it also becomes more difficult for an archer to visually determine both that distance and the proper trajectory for that distance.
Accordingly, archers use bow sights mounted on their bows to help them determine the proper trajectory. Often times, a bow sight has multiple pins, each one having been calibrated for a particular distance. The archer, while practicing at a particular distance, will manually adjust a pin for that distance. When in use, the archer will then approximate the distance to a target and determine how to compensate the trajectory based upon the knowledge of proper trajectory displayed by the multiple pins.
Some bow sights are equipped with a single pin. Often times, these bow sights are either accompanied by calibration marks or fashioned as to allow calibration marks to be made on the sight, each allowing the single pin to be adjusted manually during use to display various proper trajectories for various, corresponding distances.
With a single pin, there are problems with adjustment. Typically, the pin is mounted or positioned within or to a block. The block may be moved by the turning of a threaded shaft or other structure providing for precise positioning. If the movement of the pin or block from two positions, one being a position calibrated for a short distance and the other being a position calibrated for a distance several times the short distance, is only a slight movement, the error involved between the two positions, or between other intermediate positions, can be significant. This makes calibration difficult, if not of specious value.
If, on the other hand, the movement has a greater range, the calibration is excellent and can be done with a high degree of precision. However, as the parts that are moving (ie, the pin or block or rotating threaded shaft) are designed to be precise, this great movement typically requires effort and time that is far from ideal for some archers, for example a hunter who has just sighted quarry.
Ideally, the movement of the pin may be both tuned in very fine degrees as well as moved over a range quickly. Some presently known bow sights provide such ability.
U.S. Pat. No. 5,524,601, to Slates et al., the patent having in common the assignee and one inventor as this invention and being incorporated herein by reference, demonstrates the described ability to be tuned in very fine degrees and moved over a range quickly. This is achieved by having a vertical rotating shaft which is threaded and generally exposed, and a block that abuts and slides against a vertical bar in the direction of the central axis of the vertical rotating shaft, the block also being engaged with a sight pin. The block has a bore transverse to the direction of movement and a non-rotating shaft is positioned within the bore. The non-rotating shaft has a diametral, irregular bore through which the rotating shaft passes. The inner surface of the irregular bore matingly engages with the threads of the rotating shaft when the two are in contact, thus permitting fine tuning of the vertical position of the nonrotating shaft and, hence, the block. In addition, the bore and block are constructed, and the irregular bore has a shape, such that the non-rotating shaft may be displaced so as to disengage the bore from the rotating shaft, and thus permit the quick movement of the block and its pin in a vertical direction over a range.
The ""601 patent presents some drawbacks, however. Because the rotating shaft is necessarily exposed to slide through the block and the non-rotating shaft to protrude, the rotating shaft is susceptible to surface damage and dirt, each of which would deleteriously effect the performance, utility, and precision of the sight. Another drawback is that, because the block protrudes, the vertical bar acts as a pivot point. Accordingly, any shock against the block is directly applied as a moment force creating a sheer in the rotating shaft. This, if severe enough, could distort or damage the rotating shaft. This problem is also present for the similarly protruding non-rotating shaft.
Another known bow sight is described in U.S. Pat. No. 5,414,936, to Sappington, with a common assignee to the present invention and incorporated herein by reference. In this bow sight, again the block protrudes, as does a laterally extending shaft with a bore having a rotating shaft located therewithin. Again, this bow sight is susceptible to shock and damage that can hinder or prevent the motion of the rotating shaft.
Furthermore, U.S. Pat. No. 5,657,740, to Slates, et al., incorporated herein by reference, suffers from the same detriments of ""601, of which ""740 is a continuation-in-part.
One object of the present invention is to provide a sight for an archery bow.
Another object is to provide such a sight allowing for precision in adjusting the distance at which a pin is set.
Another object is to provide a sight allowing for quickly adjusting the distance at which a pin is set.
Another object is to provide a sight with a mechanism for translating a pin relative to the bow wherein the mechanism is minimally susceptible to damage.
These and other objects will become apparent to those skilled in the art in light of the following disclosure and accompanying drawings.
In accordance with the one aspect of the invention, generally stated, an archery bow sight assembly is provided comprising a vertically threaded rotating shaft, means for position indicia, a sight bracket including a tongue threadedly engaged with the shaft so as to respond to the shaft rotation for moving the sight bracket vertically, a pin that is displaceable so as to cooperatively disengage the tongue from the shaft thereby permitting the sight bracket to move independently of the shaft, and a pointer the position of which corresponds to the marking indicia, and means adapted for attaching a sight pin. Preferably, the archery bow sight assembly further includes a first spring and a second spring, wherein the tongue includes a bore for receiving the first spring, and wherein the pin includes a bore for receiving the second spring, the first spring directing the tongue against the shaft so that the tongue is engaged with the shaft. Preferably, the archery bow sight assembly further includes a third spring wherein the tongue further includes a second bore for receiving the third spring, the first and third springs directing the tongue against the shaft so that the tongue is engaged with the shaft. Preferably, the tongue includes a bridge portion with a sloped profile, and the pin includes a sloped notch in sliding contact with the bridge portion, depression of the pin disengaging the tongue from the shaft.
Further, in accordance with a second aspect of the present invention, an archery bow sight assembly is provided comprising a vertically threaded rotating shaft, a carriage operatively and rotatably supporting the shaft, the carriage having a cavity within which the shaft is located, the carriage having at least one face displaying marking indicia, and the carriage having one side open, and the shaft being recessed from the side open, a sight bracket closely and slidably fitted around a portion of the carriage as to permit movement of the sight bracket relative to the carriage in only the direction of the vertical axis of the carriage, the sight bracket including a tongue threadedly engaged with the shaft so as to respond to the shaft rotation for moving the sight bracket along the carriage, a pin that is displaceable so as to cooperatively dis-engage the tongue from the shaft thereby permitting the sight bracket to move independently of said shaft, and a pointer the position of which corresponds to said marking indicia, and means adapted for attaching a sight pin. Preferably, the archery bow sight assembly further comprises at least one knob secured to the shaft so as to provide means for rotating the shaft. Preferably, the knob is knurled, and preferably the knob includes a polymeric bushing in contact with said carriage. In the preferred embodiment, the carriage includes an annular projection in contact with said bushing. Preferably, the archery bow sight further includes a stop means retarding movement of the knob and shaft and providing discrete positions for the knob and shaft. In the preferred embodiment, the stop means includes a spring and a ball, and the carriage includes a bore for receiving the spring and ball, and notches for receiving the ball such that the spring and the ball retard movement of the knob and the shaft and provide discrete positions for the knob and shaft.
In accordance with a further aspect of the invention, an archery bow sight assembly is provided comprising a vertically threaded rotating shaft, a carriage operatively and rotatably supporting the shaft, the carriage having a cavity within which the shaft is located, the carriage having at least one face displaying marking indicia, and the carriage having one side open, and the shaft being recessed from the side open, a sight bracket closely and slidably fitted around a portion of the carriage as to permit movement of the sight bracket relative to the carriage in only the direction of the vertical axis of the carriage, the sight bracket including a body, at least one bracket sleeve, at least one gasket, the bracket sleeve fitted within the body in sliding contact with the carriage, the gasket fitted between the bracket sleeve and the sight bracket, and a pointer the position of which corresponds to the marking indicia, and means adapted for attaching a sight pin. Preferably, the gasket is elastomeric.